Maternal and cord blood vitamin D status in high-altitude pregnancy

We aimed to explore the risk factors that may lead to vitamin D deficiency in pregnant women living in moderately high-altitude regions.

The study was conducted prospectively between November 2012 and July 2013. City of Erzurum is located at an altitude of 1900-2200 m, north Turkey at 39°4' latitude. Healthy mothers that gave birth after completing 37th week of their pregnancies and healthy neonates weighting >2500 g were included in the study. For 25-hydroxyvitamin D (25(OH)D) analyses venous blood samples of 2 ml were obtained from the umbilical cord and the mother. Questionnaires were developed covering the demographical characteristics and possible risk factors for mothers.

Totally 81 mothers and neonates were included into the study. The mean 25(OH)D level of mothers was 7.1 ± 6.5 ng/ml. It was noted that 45 (55.7%) mothers had severe deficiency. Multivariate linear regression analysis showed that the dressing style and the level of sunlight received by the house were independent factors affecting the level of 25(OH)D.

Our findings showed that cultural factors had significant effects on vitamin D levels. We believe that appropriate dose of vitamin D prophylaxis should be administered to pregnant women, considering the risk factors as well as the geographical features.